This large Phoenix park, located south of Glendale Avenue near 20th Street, has two ponds open to urban fishing, large grassy areas with plenty of shade trees, an exercise track, and a wide perimeter of more-or-less native desert habitat. With the addition of water this park affords ample opportunities to view a variety of urban wildlife, especially birds and insects.
Four kinds of doves are abundant at Grenada Park. All doves have heads that are noticeably small in relation to the rest of the body. They characteristically bob their heads as they walk along. All four doves can be found foraging in the lawn areas, usually in small flocks. They are nipping off tender shoots, flower heads, and developing seeds from the grasses. Miniature lawn mowers with wings?
To non-bird watchers this bird is simply called a Pigeon. They were brought to America as domesticated birds and many escaped and became abundant birds in cities everywhere. Their original habitat was rocky cliffs for which man-made structers and bridges make good substitutes. Many multicolored forms have been bred over the past millenia, but most of those that breed out of captivity have reverted to the "wild-type" pattern: grey back, mantle, and tail; darker head, collar, and upper chest and often quite irridescent in the males. When cooing their mate the males puff up their upper chest of these irridescent feathers.
This is the smallest of the four. At rest the birds have distinctive scalloped markings. As they fly off, the rich, brick-red patches show in the wings. The tail is rather long with conspicuous white on the sides. In Arizona these birds are mostly restricted to cities and agricultural areas where water is readily available.
Mostly gray-brown, with a long tapered tail and a slender build. The wings produce a wistling sound as the birds fly off. Their forlorned cooing is a characteristic sound of farms and suburbs across America.
This dove is present in Arizona from April to September, after which it heads south to Mexico and Central America. It's arrival means the blistering days of summer will soon be upon us. It is considerably larger than the Mourning Dove, has a squared off tail, and as the name suggests, broad white bands in the wings. This white band is conspicuous in flight.
Like ponds everywhere, there are plenty of dragonflies. The ones patrolling back and forth over the water are mostly males. They have established territories that they defend vigorously against intruders of the same species. Body contact and vigorous chases often ensue. Female dragonflies that enter a defended patch are chased away too, unless they submit to mating. Other dragonfly species may be chased as well. At least three species were present on June 1st: (1) Flame Skimmer aka Flame Skimmer (Libullela suturata) - brick-red body with red patches in the wings; (2) Black Saddlebags (Tramea lacerata) - A dark brown bodied species with dark patches at the wing bases. (3) Sky-blue body with clear wings.
In September and October I have found Common Green Darner Dragonflies (Anax junius), including some pairs flying in tandem. The male is in front and grasps the female dragonfly just behing her neck with special claspers at the tip of his tail. The male thus escorts the female as she dips the tip of her abdomen into the water to lay eggs.
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Pale blue Damsel Flies, a small, delicate relative of dragonflies can also be found. They sit with their wings folded above their back, whereas typical dragonflies hold their wings flat. Damsel flies frequently perch on poles of quietly patient fisherman. |
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Along the south driveway there are patches of Desert Senna (Senna covesii) (about 40 cm tall) with conspicuous yellow flowers in bloom. These flowers are attractive to yellow & black Sonoran Bumble Bees (Bombus sonoras) and to a lesser extent the much larger, jet-black Carpenter Bees (Xylocopa). (These docile bees rarely sting. Unless you squish the bee or attack its nest you won't get stung. They would rather flee than fight.) The abundant bean pods of Desert Senna suggest the Bumble Bee is a good pollinator. The pods are held on the plant until they ripen and split open. They face up so that a basket is formed holding the beans inside. Only when the plant is shook by strong winds as in a thunderstorm are the seeds bounced out ..... just when it's a good time to get dispersed!
Another flower belonging to the same subfamily of legumes (Ceasalpinioideae) is also blooming in the park, Bird of Paradise (Caesalpinia gilliesii), with brilliant orange and yellow flowers on a meter tall bush. It is very fascinating to contrast the same two bees working these flowers. The nectar is down inside fied however to gather only pollen which is born at the tips of the very long stamens. The bees hover out at the ends of the stamens brushing their hairy bodies against the anthers thus gathering pollen. Later the bees rake the yellow dust up into special pollen baskets on their third pair of legs. Only a few bean pods are set because the bees just aren't designed for this flower. Rather the flower is designed to be pollinated by butterflies, especially large swallowtail butterflies, which are rare in Phoenix this year. Down Tucson way large butterflies are more abundant and so the Bird of Paradise sets a lot more seed.
| Sonoran Bumble Bee | Carpenter Bee |
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Can flies be interesting? Don't think of House Flies and Blow Flies that gather about human-generated filth! There are thousands of fly species that avoid such material, never bother people, and have fascinating stories to tell. For example, at the shore of the ponds can be found Dance Flies (Empididae) that rarely venture far from the water's edge. Male Dance Flies, roughly 5 mm, can be found guarding the tops of flat stones. They run swiftly about the rock challenging intruders to side-to-side maneuvering and head butting. Like miniature rams, they defend their right to mate with female empidids that come to lay their eggs in the mats of dead algae that have washed up on shore.
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Copyright Michael J. Plagens, 1998-2000
Updated 24 December 2004